Ad-Dukhan 44:10

<h2>Alarming the Idolators with News of the Day when the Sky will bring forth a visible Smoke</h2><p>Allah says, these idolaters are playing about in doubt, i.e., the certain truth has come to them, but they doubt it and do not believe in it. Then Allah says, warning and threatening them:</p><p>فَارْتَقِبْ يَوْمَ تَأْتِى السَّمَآءُ بِدُخَانٍ مُّبِينٍ</p><p>(Then wait you for the Day when the sky will bring forth a visible smoke.) It was narrated that Masruq said, "We entered the Masjid -- i.e., the Masjid of Kufah at the gates of Kindah -- and a man was reciting to his companions,</p><p>يَوْمَ تَأْتِى السَّمَآءُ بِدُخَانٍ مُّبِينٍ</p><p>(the Day when the sky will bring forth a visible smoke.) He asked them; `Do you know what that is' That is the smoke that will come on the Day of Resurrection. It will take away the hearing and sight of the hypocrites, but for the believers it will be like having a cold."' He said, "We came to Ibn Mas`ud, may Allah be pleased with him, and told him about that. He was lying down, and he sat up with a start and said, `Allah said to your Prophet</p><p>قُلْ مَآ أَسْـَلُكُمْ عَلَيْهِ مِنْ أَجْرٍ وَمَآ أَنَآ مِنَ …

But watch thou (O Muhammad) for the day when the sky will produce visible smoke

Then watch thou for the Day that the sky will bring forth a kind of smoke (or mist) plainly visible,

Then wait you for the Day when the sky will bring forth a visible smoke.

So watch out for the Day when the sky produces a visible smoke.